// From Perl's Time::Timezone
$pc_timezones = array(
  'GMT'  =>   0,           // Greenwich Mean
  'UTC'  =>   0,           // Universal (Coordinated)
  'WET'  =>   0,           // Western European
  'WAT'  =>  -1*3600,      // West Africa
  'AT'   =>  -2*3600,      // Azores
  'NFT'  =>  -3*3600-1800, // Newfoundland
  'AST'  =>  -4*3600,      // Atlantic Standard
  'EST'  =>  -5*3600,      // Eastern Standard
  'CST'  =>  -6*3600,      // Central Standard
  'MST'  =>  -7*3600,      // Mountain Standard
  'PST'  =>  -8*3600,      // Pacific Standard
  'YST'  =>  -9*3600,      // Yukon Standard
  'HST'  => -10*3600,      // Hawaii Standard
  'CAT'  => -10*3600,      // Central Alaska
  'AHST' => -10*3600,      // Alaska-Hawaii Standard
  'NT'   => -11*3600,      // Nome
  'IDLW' => -12*3600,      // International Date Line West
  'CET'  =>  +1*3600,      // Central European
  'MET'  =>  +1*3600,      // Middle European
  'MEWT' =>  +1*3600,      // Middle European Winter
  'SWT'  =>  +1*3600,      // Swedish Winter
  'FWT'  =>  +1*3600,      // French Winter
  'EET'  =>  +2*3600,      // Eastern Europe, USSR Zone 1
  'BT'   =>  +3*3600,      // Baghdad, USSR Zone 2
  'IT'   =>  +3*3600+1800, // Iran
  'ZP4'  =>  +4*3600,      // USSR Zone 3
  'ZP5'  =>  +5*3600,      // USSR Zone 4
  'IST'  =>  +5*3600+1800, // Indian Standard
  'ZP6'  =>  +6*3600,      // USSR Zone 5
  'SST'  =>  +7*3600,      // South Sumatra, USSR Zone 6
  'WAST' =>  +7*3600,      // West Australian Standard
  'JT'   =>  +7*3600+1800, // Java 
  'CCT'  =>  +8*3600,      // China Coast, USSR Zone 7
  'JST'  =>  +9*3600,      // Japan Standard, USSR Zone 8
  'CAST' =>  +9*3600+1800, // Central Australian Standard
  'EAST' => +10*3600,      // Eastern Australian Standard
  'GST'  => +10*3600,      // Guam Standard, USSR Zone 9
  'NZT'  => +12*3600,      // New Zealand
  'NZST' => +12*3600,      // New Zealand Standard
  'IDLE' => +12*3600       // International Date Line East
);